In a state radio statement, Capt Moussa Dadis Camara said a "consultative council"
of civilian and military leaders would be set up in their place.

All ministers and other top officials have been summoned to the main military camp "
to guarantee their security".

Mr Conte had ruled the West African country with an iron fist since 1984.
The precise circumstances of the president's death are not yet known,
but he had been suffering from diabetes.

BBC West Africa correspondent Will Ross says it is important to see whether
the army is united on the way forward for Guinea, as a power struggle could
be extremely dangerous given the deep ethnic divisions there.

Guinea's neighbours - Liberia, Sierra Leone and Ivory Coast - are enjoying
relative stability after many years of brutal conflict, and there are fears that
any unrest there could spread across the borders and embroil the sub-region
in fighting once more.

Prime Minister Ahmed Tidiane Souare earlier appealed for "calm and restraint"
and declared 40 days of national mourning.

"I call on the defence and security forces to assure the security of our borders
and calm inside national territory in homage to the memory of the illustrious
late leader," he said.

Only hours after the speaker of parliament announced that President Conte
had died after a "long illness", Capt Camara went on state radio to say that
the army had taken over, and a body called the National Council for
Democracy and Development (CNDD) set up.

"As of today, the constitution is suspended as well as political and union
activity," he said. "The government and the institutions of the republic have
been dissolved.

"In the next few days, a transitional consultative council will be set up made
up of soldiers and civilians taking account of ethnic balance," he added.

The council will then name a military leader as president and a civilian as
prime minister.

Capt Camara said the country was in a state of "deep despair" and that it was
vital that something was done to improve the economy and combat corruption.

"The institutions of the republic have shown themselves to be incapable of
resolving the crises which have been confronting the country," he said.

Announcers said the captain, who is head of the army's fuel supplies unit,
was speaking on behalf of the entire military, although this has not been
independently confirmed.

A later statement by the CNDD told ministers to present themselves at the
Alfa Yaya Diallo military camp, "in order to guarantee their security", and
ordered the population to "stay at home and refrain from all acts of
vandalism and looting".

Where I am is unusually quiet save for the noises of passing vehicles and
there are very few BBC correspondent Alhassan Sillah, Conakry
"Public assemblies are formally forbidden," it added.

The BBC's Alhassan Sillah in the capital, Conakry, said there is little sign
of troops on the streets.

"Where I am is unusually quiet save for the noises of passing vehicles and
there are very few," he told the BBC's Network Africa programme.

"I've not seen one single child in school uniform and nor have I seen those
women who should be going to the market as of now."

Earlier, the leader of the Union for the Progress of Guinea and the secretary
of the opposition alliance, Frad, Jean-Marie Dore, called for a peaceful transition of power:

Veteran opposition leader Alpha Konde returned to Guinea on Sunday
after 15 months of self-imposed exile in France. He left Guinea after
being released from jail.

The African Union's peace and security commissioner, Ramtane Lamamra,
told the AFP news agency that it was "pre-occupied and keenly monitoring"
the developments in Conakry.

"We urge all the political and other state institutions in Guinea, especially the
armed forces, to ensure a constitutional, peaceful and consensual transition t
hat respects democratic order," he said.

Will Ross says that according to the constitution, National Assembly Speaker
Aboubacar Sompare should be in charge until fresh elections are held
within 90 days, but what appears to be a coup d'etat has changed that.

Despite Guinea's mineral wealth, it is one of West Africa's poorest nations
Many analysts had predicted that the army would take over following
Mr Conte's death because he had been increasingly relying on it to
shore up his oppressive rule, our correspondent says.

President Conte, a diabetic and chain smoker, had been ill for several years.
Although it was never officially revealed, he was believed to have been
suffering from leukaemia.

He came to power in 1984 at the head of a military coup to fill the power vacuum
that had been left by the sudden death of his predecessor, Sekou Toure,
who had been president since independence from France in 1958.

He eventually oversaw a return to civilian rule and was elected three times,
although critics said the votes were never free or fair.

As his health declined over the last five years, it was often far from clear
who was in charge and the government barely functioned, our correspondent says.

Some political parties were allowed to operate, but many opposition leaders were either intimidated by the authorities or jailed.

Last year, more than 150 people were shot dead by the police and the army
when demonstrators took to the streets calling for change.

A further four people were killed following protests in the suburbs of Conakry
in November, according to Human Rights Watch.

Although Guinea's mineral wealth and fertile soil makes it potentially one of
Africa's richest countries, its eight million people are among the poorest in the region.